Transposition bracket



Sept. e, 1955 R, SE 2,717,274

TRANSPOSITION BRACKET Filed June 21, 1951 2 Sheets-Sheet 1 a &

Jam 770,3 1730 61 5 Case wwzm 7Q. 97%

Sept. 6, 1955 R. CASE TRANSPOSITION BRACKET 2 Sheets-Sheet 2 Filed June2.1, 1951 a gept. 8, HESS fiice TRANSPOSITION BRACKET Rogers Case,Orange, N. J.; Ethel Case, executrix of the estate of said Rogers Case,deceased, assignor to Transandean Associates, Inc., Orange, N. .l., acorporation of Delaware Application June 21, 1951, Serial No. 232,737

4 Claims. (Cl. 174-413) This invention relates to a bracket fortransposing the paired wires of communication lines.

In modern communication systems it is general practice to transposepaired line wires at spaced intervals, to minimize noises on the linesand cross-talk. This transposition is of particular advantage in theso-called phantom and carrier circuits and in the carrier circuits exactspacing of the transposition points regardless of the spacing of theline poles is a matter of importance. In transposition bracketsgenerally considered it is highly desirable that the spool-forminsulators against which the wires are brackets of both the point andspan types which pro- 1 vide a clevis mounting for rotatable insulatorstogether with adequate structural strength enduringly to sustain thethrust of the wires.

It is an object of my present invention to provide a transpositionbracket having rotatable clevis-mounted insulators and providing spacewithin the bounds of the bracket for crossing the wires at differentlevels, which bracket while being of adequate strength is economical inthe amount of metal included in its structure and lends itself tosimplicity and economy in manufacture.

Another object of my invention is to provide a transposition brackethaving the above-noted qualifications which is usable with but slightand obvious modification either as a span bracket or as a point bracket.

In the accompanying drawings illustrative of the embodiment of myinvention:

Fig. l is a plan view of my transposition bracket, showing a pair ofline wires transposed thereby.

Fig. ll is a fragmentary end elevation showing the mounting of theinsulators at one end of the bracket.

Fig. III is a vertical-sectional view taken in the plane of the sectionline Ill-4H of Fig. I and looking in the same direction as in Fig. ll.

Fig. 1V is a side elevation of the bracket looking from the right inFig. I.

Fig. V is a fragmentary plan view showing the adaptation of mytransposition bracket for mounting on the cross-arm of a line pole as apoint bracket.

With reference to the drawings, the primary supporting structure of thebracket is in the form of a cradle. The cradle comprises two basemembers 1 and 2 which are spaced from each other the desired width or"the bracket and which provide mounting for the clevis forming members ofthe bracket structure. These base members 1 and 2 are connected by twoarms 3 and 4 which are inclined convergently downward and are connectedby a foot 5 which forms the lowermost portion of the bracket proper.Desirably as shown, the cradle comprising the base members, convergentarms and foot is a one piece strap-form bar and desirably the basemembers 1 and 2 are plates which lie in a common horizontal plane.

Four clevises are formed for the rotatable mounting of four spool-forminsulators in diagonally matching high and low pairs with respect to thebase provided by the base plates 1 and 2. With respect to base plate 1specifically considered and as shown particularly in Fig. ll of thedrawings, two strap-form bars 6 and 7 are secured to that member as bymeans of rivets S. Each of bars 6 and 7 has the general contour of aflanged channel in side elevation comprising int rmediate region a forattachment to its base plate and two relatively flat offset regions 17and c joined to intermediate region a by angularly extended legs d and ewhich are of unequal length. It will be noted that bars 6 and 7 areattached respectively at the upper and lower faces of the base plate andthat they are in reversed relation with respect to the position of theirlonger legs d and shorter legs e. The result is to provide to one sideof the base plate a higher clevis 9 the major proportion of which liesabove the plane of the base and at the other side of the base plate alower clevis 10 the major proportion of which lies below the plane ofthe base.

At the other end of the bracket, shown in Fig. III of the drawings, asecond pair of similarly shaped bars 11 and 12 are similarly secured tobase member 2 as by rivets 8. These bars 11 and 12 also comprise each anintermediate region a and two relatively flat regions b and c joined tothe intermediate region of the bar by longer legs (1 and shorter legs arespectively. The bars 11 and 12, like the bars 6 and '7 lie at oppositefaces of the base member to which they are secured with their longer andshorter legs oppositely arranged. This arrangement givesinsulator-mounting clevises 13 and 14 between strap-form bars 11 and 12.Whereas at the end of the bracket shown in Fig. H the bars 6 and 7 areso arranged that the relation of their longer and shorter legs gives ahigh clevis 9 to the left in the drawing and low clevis iii) to theright in the drawings, at the end of the bracket shown in Fig. III thearrangement of the bars is such as to give an opposite arrangement ofthe clevises l3 and 14. Thus as shown in Fig. Til, the low clevis 13 isto the left in the drawing and the high clevis 14 is to the right.

Taking the bracket as a whole, the relative arrangement of the bars 6and 7 at one end of the bracket and the arrangement of the bars 11 and12 at the opposite end of the bracket gives a diagonal matching of highinsulator-mounting clevises 9 and 14 and low insulator mounting clevises10 and 13. To equip the bracket frame for use as a complete bracket,four spool-form insulators 15, 16, 1'7 and 18 are mounted rotatably inthe four clevises 9, 1t), 13, and 14 respectively by means of insulatorpins 19. It is to be understood that the insulators either may rotate ontheir pins 19, the pins may be rotatable in holes 20 in the regions I)and c of the clevis-forming bars or both the pins and insulators may berotatable with respect to each other and to the frame structure of thebracket. Returning to consideration of the general bracket assembly, thearrangement of the insulator-mounting clevises in the bracket framecauses the diagonal pair of insulators 1S and 13 to project chieflyabove the base plane of the bracket and the insulators 16 and 17 toproject chiefly below the base plane of the bracket.

The diagonally matched mounting of high and low wire-training insulatorsprovides for the crossing of two line wires in vertically spacedrelation. Room for the spaced crossing of the wires in their verticallyspaced relation and within the bounds of the bracket is provided by theform of the bracket cradle, the arms 3 and 4 of which decline sharplyfrom the base plane of the bracket to the foot 5 of the cradle, so thatthe lowermost of the two wires is out of contact with the cradlestructure. The use of the transposition bracket is shown in Fig. l ofthe drawings, in which one line wire A is trained on low insulators 16and 17 and the other line wire B is trained on high insulators 15 and18, with the wires crossed within the bounds of the bracket. As will beapparent, the position of the wires is such that they can be brought byrelative lateral movement of the Wires or the bracket into contact withthe insulators within the bounds of the outwardly open clevises in Whichthe insulators are mounted.

When the bracket is used as a span bracket, it is placed in suchrelation with the line wires in a region between the line poles that thewires are crossed within the bounds of the bracket and the bracket issuspended from the wires. In this relation of the bracket in the line,the rotatable mounting of the wire-training insulators provides forready movement of the bracket into adjusted position along the line. Inthe suspended relation of the bracket with the line wires the cradlestructure extends downwardly and functions as a balance to preventswinging of the wires and possible inversion of the bracket under theweight of accumulated ice or trash.

The bracket cradle also provides for simple adaptation of the bracketfor use as a point bracket to be mounted on the cross-arm of a line poleas in Fig. V of the drawings. To equip the bracket for such use it isnecessary merely to secure attaching means such as attachment plate 2.1to the foot 5 of the bracket cradle, as by rivets 22. Desirably holes 23are preformed in foot 5 of the cradle for this purpose. In utilizationof my transposition bracket as a point bracket, the rotatable mountingof the insulators facilitates the operation of drawing the line wirestight by a simple longitudinal pull at the pole where the bracket isinstalled.

It is possible and under some conditions desirable to cast the bracketframe in one piece of one of the light metals such as aluminum,magnesium and their alloys. In such case savin in the weight of includedmetal results from the form of the bracket frame. Particular advantagesare obtained when using ferrous metal to fabricate the bracket frame asherein specifically shown and described. The cradle of the frame is aone-piece structure which can be made in a single die-pressingoperation. The

four strap-form bars which make the insulator-mounting clevises areidentical and can be formed in a single die common to all of them. Thesefacts give great manufacturing economy under all conditions and theidentity in contour of the elevis-forming bars is of particularadvantage. If in any installation of brackets it is desired to providean altered vertical spacing of the wires crossed within the bounds ofthe bracket, it is necessary merely to provide one changed die to givean altered relation between the longer and shorter connecting legs d andc of all the clevis-forming bars.

The simplicity of the frame structure lends itself naturally to economyin the weight of metal included in the bracket frame. Whether it befabricated as shown or made as a one-piece casting the form of thecradle increases the utility of the bracket frame. The downwardconvergence of the cradle legs with interconnection at the lower end ofthe legs gives the effect of a cantilever and greatly increases theresistance of the frame to tortional stresses caused by the thrust ofthe wires. This is one contributing factor to economy in the weight ofmetal included in the bracket frame.

As used herein the terms horizontal, lowermost, downward, end, side andthe like refer to what may be considered the normal position of thebracket in a line the wires of which are transposed by the bracket inaccordance with preexisting general practice.

Having disclosed one embodiment of my invention, it is to be understoodthat changes in material, structure and arrangement may be made withinthe bounds of the invention as defined in the statement of the claimsappended hereto.

I claim as my invention:

1. A transposition bracket for paired line wires the frame structure ofwhich comprises a central cradle having two arms of approximately equallength downwardly convergent and interconnected at their lower ends andtwo relatively spaced base members on said arms in a common horizontalplane, two bars secured on opposite faces of each of said base members,said two bars associated with each of the said base members having atboth ends thereof offset regions at different levels with respect to thebase member, the offset regions of the two said bars being superposedand spaced vertically from each other to provide two outwardly openinsulator-mounting clevises extending one chiefly below and the otherchiefly above the horizontal plane of the said associated base member,the relative arrangement of the said clevisforming bars being reversedat the two said horizontally spaced base members of the bracket to givea diagonal matching of higher and lower clevises, and spool forminsulators rotatably mounted in the said four clevises of the bracketfor crossing of the two line wires at different levels within the cradleof the bracket.

2. A frame structure for a transposition bracket for paired line wirescomprising a central cradle having two arms of approximately equallength downwardly convergent and interconnected at their lower ends andtwo relatively spaced base members on said arms in a common horizontalplane, two bars on opposite faces of each of said base members, said twobars associated with each of the said base members each having at bothends thereof offset regions at different levels with respect to the basemember, the offset regions of the two said bars being superposed andspaced vertically from each other to provide two outwardly openinsulator-mounting clevises one extended chiefly below and the otherchiefly above the horizontal plane of the said associated base member,the relative arrangement of the said clevis-forming bars being reversedat the two said horizontally spaced base members of the bracket to givea diagonal matching of higher and lower clevises.

3. A frame structure for a transposition bracket for paired line wirescomprising a single central cradle having two downwardly convergent armsof approximately equal length and an interconnecting foot at the lowerends of said arms, and two insulator-mounting structures on the upperends of the said arms of the cradle, the said insulator-mountingstructures each being extended in opposite horizontal directions fromits associated arm of the cradle and each being forked at both its endsto provide two outwardly open insulator-mounting clevises, the said twoclevises of each insulator-mounting structure being at different levelswith respect to the foot of the said cradle and the four clevisesprovided by the two insulator-mounting structures being oppositelyarranged on the two said arms with respect to the said higher and lowerlevels of the clevises, to give a diagonal matching of the higher andlower insulator-mounting clevises in the structure of the frame.

4. A transposition bracket for paired line wires the frame structure ofwhich comprises a single central cradle having two downwardly convergentarms of approximately equal length and an interconnecting foot at thelower ends of said arms, two insulator-mounting structures on the upperends of the said arms of the cradle, the said insulator-mountingstructures each being extended in opposite horizontal directions fromits associated arm of the cradle and each being forked at both its endsto provide two insulator-mounting clevises, the said two clevises ofeach insulator-mounting structure being at different levels with respectto the foot of the said cradle and the four clevises provided by the twoinsulatormounting structures being oppositely arranged on the two saidarms with respect to the said higher and lower 5 6 levels of theclevises, to give a diagonal matching of the References Cited in thefile of this patent higher and lower insulator-mounting clevises in thestruc- UNITED STATES PATENTS ture of the frame, and spool formlnsulators rotatably mounted in the said four clevises in the bracketfor cross- 1,840,362 Hunter et a1 1932 ing of the two line Wires atdifferent levels within the 5 2,437,593 Case 1948 cradle of the bracket2,455,229 case N v. 30, 1948

